检索结果-南通市图书馆

Spatial and Temporal Patterns of Variation in Environmental Quality of Water and Sediments of Streams in Mined and Unmined Areas with Emphasis on Mercury (Hg) and Arsenic (As)

引用

Journal of Geoscience and Environment Protection 2018年第9期6卷 125-140页

作者： Stephen T. Annan Peter O. Sanful George Lartey-Young rebecca k. yandam Department of Science SDA College of Education Asokore Koforidua Ghana Department of Fisheries and Water Resources University of Energy and Natural Resources Sunyani Ghana Department of Environmental Science University College of Agriculture and Environmental Studies Bunso Ghana Zoomlion Ghana Limited Jospong Group of Companies Tamale Ghana

Heavy metal pollution from both anthropogenic and natural processes can have significant effect on environmental quality of stream and river systems. However, in Ghana, heavy metal pollution of waterbodies is attributed mainly to mining activities but the role of natural mechanisms in altering stream water and sediment quality in relation to heavy metals has received little attention. Spatial and temporal variation in water quality parameters and heavy metal concentrations in water and sediments were studied comparatively in a river and two streams in a gold-rich watershed impacted by heavy mining activities. Samples were collected monthly over a twelve-month period from November 2010 to October 2011 from upstream (unmined) and downstream (mined) sections of the studied streams. Parameters measured include temperature, dissolved oxygen, conductivity, pH, turbidity, colour, mercury (Hg) and arsenic. High spatial variability of water quality parameters was found. Hg concentrations in water were extremely low in both upstream and downstream areas. Maximum geochemical back.round levels of Hg in unmined pristine areas were 2.45 mg/g whilst arsenic was 29.10 mg/g. By contrast, gold-mined downstream areas recorded Hg and arsenic concentrations of 8.75 mg/g and 82.53 mg/g in stream sediments respectively. Levels of Hg and arsenic in sediments were several orders of magnitude greater than concentrations in surface water in downstream sections and this may be explained by substances originating from mining activities, upstream transport or remobilized sedimented materials in the overlying water column. Our study showed that both natural and human activities may contribute to heavy metal pollution in the highly mineralized watershed of the Pra River Basin. Human factors are however lik.ly to amplify the natural back.round levels of heavy metals.

关键词： Water Quality Mining Mercury Arsenic Stream Sediments

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Multisensory mechanisms of gait and balance in Park.nson’s disease:an integrative review

引用

Neural Regeneration Research 2025年第1期20卷 82-92页

作者： Stiven Roytman rebecca Paalanen Giulia Carli Uros Marusic Prabesh k.nel Teus van Laar Nico I.Bohnen Department of Radiology University of MichiganAnn ArborMIUSA Department of Neurology University of MichiganAnn ArborMIUSA Morris k.Udall Center of Excellence for Park.nson’s Disease Research University of MichiganAnn ArborMIUSA Institute for k.nesiology Research Science and Research Centre KoperKoperSlovenia Department of Health Sciences Alma Mater Europaea–ECMMariborSlovenia Park.nson’s Foundation Research Center of Excellence University of MichiganAnn ArborMIUSA Department of Neurology University of GroningenUniversity Medical Center GroningenGroningenThe Netherlands Neurology Service and GRECC VA Ann Arbor Healthcare SystemAnn ArborMIUSA

Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging *** and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous *** effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory *** mechanisms which underpin the integration of these multisensory signals are the principal topic of the present *** multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older *** emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and *** the present work.we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Park.nson’s *** also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk.in older ***,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.

关键词： aging balance encephalography functional magnetic resonance imaging gait multisensory integration Park.nson’s disease positron emission tomography somatosensory vestibular visual

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Locally advanced pancreatic cancer: staging, operability, and the importance of multimodality therapy

引用

Hepatobiliary Surgery and Nutrition 2020年第4期9卷 497-500页

作者： rebecca Y.k.m Douglas B.Evans k.thleen k.Christians Department of Surgery and the LaBahn Pancreatic Cancer Program Medical College of WisconsinMilwaukeeWIUSA

The role for surgery in the management of locally advanced pancreatic cancer(LAPC)is nicely discussed in the manuscript by Gemenetzis et *** in the Annals of Surgery(1).As the authors ack.owledge,therapeutic selection... 详细信息

关键词： Surgery cancer al.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Do males choose their mates in the lek.ing moth Achroia grisella？ Influence of female body mass and male reproductive status on male mate choice

引用

Insect Science 2018年第5期25卷 861-868页

作者： Marlene Goubault rebecca Burlaud Institut de Recherche sur la Biologie de I'Insecte UMR 7261 CNRS-Universite Francois-Rabelais Tours France

Lek.ing males aggregate to attract females and contribute solely to egg fer- tilization, without any further parental care. Evolutionary theory therefore predicts them to be nonchoosy toward their mates, because any lost mating opportunities would out- weigh the benefits associated with such preferences. Nevertheless, due to time costs, the production of energetically costly sexual displays, and potential sperm limitation, the mat- ing effort of lek.ing males is often considerable. These factors, combined with the fact that many females of varying quality are lik.ly to visit lek., could favor the evolution of male mate preferences. Here, we show that males of the lek.ing lesser wax moth, Achroia grisella, were indeed more lik.ly to mate with heavier females in choice experiments, even at their virgin mating （i.e., when their reproductive resources have not yet been depleted by previous matings）. This differential female mating success could not be attributed to female behavior as heavy and light females showed similar motivation to mate （i.e., la- tency to approach the males） and time to copulate. Males seem to benefit from mating with heavier females, as fecundity positively correlated with female mass. This new em- pirical evidence shows that male mate choice may have been tmderestimated in lek.ing species

关键词： fecundity lek lesser wax moth mate choice mating status sexual behavior

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Last electroweak.WIMP standing: pseudo-dirac higgsino status and compact stars as future probes

引用

Chinese Physics C 2018年第4期42卷 117-134页

作者： rebecca k.all Matthew Reece Department of Physics Harvard University

Electroweak.WIMPs are under intense scrutiny from direct detection, indirect detection, and collider experiments. Nonetheless the pure（pseudo-Dirac） higgsino, one of the simplest such WIMPs, remains elusive. We present an up-to-date assessment of current experimental constraints on neutralino dark.matter. The strongest bound on pure higgsino dark.matter currently may arise from AMS-02 measurements of antiprotons, though the interpretation of these results has sizable uncertainty. We discuss whether future astrophysical observations could offer novel ways to test higgsino dark.matter, especially in the challenging regime with order Me V mass splitting between the two neutral higgsinos. We find that heating of white dwarfs by annihilation of higgsinos captured via inelastic scattering could be one useful probe, although it will require challenging observations of distant dwarf galaxies or a convincing case to be made for substantial dark.matter content in ω Cen, a globular cluster that may be a remnant of a disrupted dwarf galaxy. White dwarfs and neutron stars give a target for astronomical observations that could eventually help to close the last, most difficult corner of parameter space for dark.matter with weak.interactions.

关键词： dark.matter higgsino supersymmetry

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Characterization of energy and performance of swine fed a novel corn-soybean extruded product

引用

Journal of Animal Science and Biotechnology 2015年第3期6卷 322-329页

作者： k.therine M k.ch Robert C Thaler Sam k.Baidoo Crystal L Levesque rebecca C Bott South Dak.ta State University University of Minnesota Southern Research and Outreach Center

Back.round： A novel extruded product was characterized with a metabolism and lactation trial to establish the product＇s energy content, and its effects on lactating sow performance. The product was composed of a 60：40 corn-soybean blend, which was then extruded. This product containing the co-extruded 60：40 corn-soybean blend was commercially developed and is used extensively in swine diets in southwest Minnesota. GE of dietary treatments were determined by isoperibol bomb calorimetry. Twelve barrows （59.9 ± 1.4 k.）, were used to determine the digestible and metabolizable energy of the extruded product. DE of treatments was determined by subtracting fecal energy from GE provided to barrows by each respective treatment. ME was determined by subtracting urinary energy from calculated digestible energy. Sixty-three sows were used for the lactation trial. Three dietary treatments were utilized： CONTROL （an industry standard diet）; PRODUCT （contained the product, vitamins and minerals）; OIL （matched the lysine：ME ratio of PRODUCT by addition of soy oil）. Sow weight, back.at thick.ess at the right and left last ribs, body condition score, number of piglets, and litter weights were recorded on the date of farrowing （d 0）, （d 9）, and at weaning. Blood and milk.samples were obtained at weaning, and blood was analyzed for plasma urea nitrogen （PUN）, milk.was analyzed for total protein and fat content. Results： On a dry-matter basis, the test diet provided 3,908 k.al/k. DE and 3,833 k.al/k. ME, which was significantly greater than the basal diet, which provided 3,633 k.al/k. DE and 3,567 k.al/k. ME （P 〈 0.0001）. These data were used to establish the DE and ME of the product, which were 3,882 k.al/k. and 3,798 k.al/k., respectively, on an as-fed basis. No effect of diet was observed for changes in sow back.at （RBF P = 0.24; LBF P = 0.07） or body condition score （P = 0.12） during lactation. Milk.total protein （P = 0.69）, fat （P = 0.66）, PUN, average piglet gain （P = 0.55） and pi

关键词： Corn Extruded Lactation ME Soybean Swine

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Update on nutritional status,body composition and growth in paediatric inflammatory bowel disease

引用

World Journal of Gastroenterology 2014年第12期20卷 3191-3197页

作者： rebecca J Hill Children’s Nutrition Research Centre Queensland Children’s Medical Research Institute The University of QueenslandHerston School of Medicine The University of QueenslandHerston

Growth and nutritional status are important issues in paediatric inflammatory bowel disease(IBD).While linear growth is easy to assess,nutritional status is more complicated,with reports often compromised by the use of simple measures,such as weight and the body mass index,to assess nutritional status rather than more appropriate and sophisticated techniques to measure body *** review is an update on what is currently k.own about nutritional status as determined by body composition in paediatric ***,this review will focus on the impact of biologics on growth in paediatric *** lean mass deficits have been reported in children with IBD compared with controls,and there is evidence these deficits persist over ***,data imply that gender differences exist in body composition,both at diagnosis and in response to *** respect to growth improvements following treatment with biologics,there are conflicting *** some studies report enhancement of growth,others do *** relationship between disease severity,impaired growth and the requirement for biologics needs to be considered when interpreting these ***,k.y features associated with improvements in growth appear to be successful clinical response to treatment,patients in early stages of puberty,and the presence of growth failure at the onset of treatment.

关键词： Crohn’ s disease, Ulcerative colitis, Lean mass, Pubertal status, Infliximab, Inflammatory bowel disease

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Future applications of exosomes delivering resolvins and cytok.nes in facilitating diabetic foot ulcer healing

引用

World Journal of Diabetes 2023年第1期14卷 35-47页

作者： Joshua P B Littig rebecca Moellmer Devendra k.Agrawal Vik.ant Rai Translational Research Western University of Health SciencesPomonaCA 91766United States College of Podiatry Western University of Health SciencesPomonaCA 91766United States

Type 2 diabetes mellitus(T2DM)increases the risk.of many lethal and debilitating *** them,foot ulceration due to neuropathy,vascular disease,or trauma affects the quality of life of millions in the United States and around the *** wound healing is stalled in the inflammatory phase by the chronicity of inflammation without proceeding to the resolution *** advanced treatment,diabetic foot ulcers(DFUs)are associated with a risk.of ***,there is a need for novel therapies to address chronic inflammation,decreased angiogenesis,and impaired granulation tissue formation contributing to the non-healing of *** have shown promising results with resolvins(Rv)and anti-inflammatory therapies that resolve inflammation and enhance tissue *** many of these studies have encountered difficulty in the delivery of Rv in terms of efficiency,tissue targetability,and *** review summarized the perspective of optimizing the therapeutic application of Rv and cytok.nes by pairing them with exosomes as a novel strategy for targeted tissue delivery to treat non-healing chronic *** articles discussing the T2DM disease state,current research on Rv for treating inflammation,the role of Rv in enhancing wound healing,and exosomes as a delivery vehicle were critically reviewed to find support for the proposition of using Rv and exosomes in combination for DFUs *** literature reviewed suggests the beneficial role of Rv and exosomes and exosomes loaded with antiinflammatory agents as promising therapeutic agents in ulcer healing.

关键词： Diabetic foot ulcer Chronic inflammation Amputation Exosomes Cytok.nes Resolvins

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Increased Benthic Algal Primary Production in Response to the Invasive Zebra Mussel (Dreissena polymorpha) in a Productive Ecosystem,Oneida Lak.,New York

引用

Journal of Integrative Plant Biology 2008年第11期50卷 1452-1466页

作者： rebecca k.Cecala Christine M.Mayer k.mberly L.Schulz Edward L.Mills Biology Department Syracuse University Biology Deptartment Department of Environmental Sciences and Lak. Erie Center University of Toledo State University of New York School of Environmental Science and Forestry Cornell Biological Field Station and Department of Natural Resources Cornell University

Increased water clarity associated with zebra mussel （Dreissena polymorpha） populations may favor benthic algal primary production in freshwater systems previously dominated by pelagic phytoplank.on production. While zebra mussel-mediated water clarity effects on benthic primary production have been implicated in published reports, few production estimates are available. This study estimates benthic primary production in Oneida Lak., NY before and after zebra mussel invasion （1992）, using measured photosynthetic parameters （P^Bmax, α^β and β） from sampled benthic algal communities. In the summers of 2003 and 2004, primary production was measured as O2 evolution from algal communities on hard （cobble） and soft （sediment） substrate from several depths. We also back.ast estimates of benthic primary production from measurements of light penetration since 1975. Estimates of whole-lak. epipelic and epilithic algal primary production showed a significant （4%） increase and exhibited significantly less interannual variability subsequent to the establishment of zebra mussels. We applied our model to two lak.s of differing trophic status; the model significantly overestimated benthic primary production in a hypereutrophic lak., but there was no significant difference between the actual and predicted primary production values in the oligotrophic lak.. The hypereutrophic lak. had higher zebra mussel densities than Oneida （224 vs. 41 per sample respectively）. Though total community respiration （measured in total dark.ess） was factored into our model predictions of production, our model may need modification when heterotrophic respiration is a large portion of total community metabolism.

关键词： Dreissena ecosystem engineering nonindigenous species Oneida Lak. periphyton primary production.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impaired cellulose decomposition in a headwater stream receiving subsurface agricultural drainage

引用

Ecological Processes 2022年第1期11卷 845-861页

作者： rebecca Poisson Adam G.Yates Department of Geography Western UniversityLondonONCanada Department of Biology University of WaterlooWaterloo University200 University Avenue WestWaterlooON N2L 3G1Canada

Back.round:Agricultural development of former wetlands has resulted in many headwater streams being sourced by subsurface agricultural drainage *** drainage inputs can significantly influence stream environmental conditions,such as temperature,hydrology,and water chemistry,that drive ecological ***,ecological assessments of subsurface drainage impacts are *** assessed the impact of an agricultural drainage system on cellulose decomposition and benthic respiration using a paired stream study in a headwater branch of Nissouri Creek.in Ontario,*** first order segments sourced by a spring-fed marsh and a cropped field with subsurface drainage,as well as the adjoining trunk.segment,were sampled over a year using the cotton strip assay to measure cellulose decomposition and benthic ***:Assessments of cellulose decomposition revealed a one-third reduction in the drainage-sourced segment compared to marsh-sourced *** segment differences in cellulose decomposition were associated with reduced summer temperatures in the drainage-sourced *** of stream cooling from the drainage-sourced segment were transmitted downstream as cellulose decomposition was slower than expected throughout the drainage-sourced segment and for several hundred meters down the adjoining trunk.*** respiration only differed between the drainage-and marsh-sourced segments in spring,when stream temperatures were ***:Our findings suggest there may be a widespread reduction in cellulose decomposition in streams across similar agricultural regions where subsurface drainage is ***,cooling of streams receiving significant amounts of water inputs from subsurface drainage systems may impart increased resiliency to future climate warming.

关键词： Stream Agriculture Cotton strip assay Seasonality Organic matter break.own Benthic respiration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：